Patent Number: 6,529,156

Title: Self calibration of transponder apparatus

Abstract: A method and apparatus is provided for remotely and constantly calibratinga transponder by using the ring around phenomenon. A number of differenttime varying physical quantities, such as for example temperature, signallevel, noise, transmission line flex, frequency, and general operationaleffects, affect the inherent delay in transponders on a time varyingbasis. The invention relies on a the ring around phenomenon to producepulse doublets, wherein the distance between the pulses in the pulsedoublets correspond to the instantaneous delay in the transponder. Thesystem is configured so that instantaneous variation in the transmissiondelay is detected and recognized on a pulse by pulse basis and transmittedto the interrogation device, which then functions to calculate the actualdelay. Normal operation of the transponder is not affected by thecontinuous calibration method, and therefore a special calibration mode isnot required.

Inventors: Morchel; Herman G. (Nutley, NJ), Kocian; Donald J. (Springfield, MO), Diecke; Dietrich W. (New Providence, NJ)


International Classification: G01S 13/76 (20060101); G01S 13/00 (20060101); G01S 7/40 (20060101); G01S 007/40 (); G01S 013/74 ()

Expiration Date: 03/02015